BOOK    CLIFFS    COAL    FIELD,    UTAH.  297 
that  mining  machines  can  not  be  successfully  used.  The  roof  is  usually  sandstone.  Thin 
shales  occur  locally  at  the  contact  of  the  coal.  The  quality  of  the  Castlegate  coal  is  shown 
by  analyses  Nos.  7  and  8  of  the  table  (p.  294).  The  mine  has  been  driven  through  the  ridge 
in  places  to  a  fringe  of  burned  coal.  The  width  of  the  burned  area  varies  and  the  high  tem- 
perature of  the  rock  in  places  where  the  boundary  is  approached  indicates  that  spontaneous 
combustion  of  the  coal  probably  has  not  entirely  ceased. 
Sprint/  Canyon. — The  lowest  workable  coal  in  the  series  is  opened  in  two  small  mines  in 
sec.  9,  T.  13  S.,  R.  9  E.  The  first,  known  locally  as  the  Rhodes  mine,  is  near  the  center  of 
the  section  in  the  gulch  leading  into  Spring  Can  von.  The  coal  is  in  three  parts  and  the 
section  is  as  follows: 
Section  at  Rhodes  mine. 
Ft.    in. 
1.  Sandstone,  partially  exposed. 
2.  Shale 4 
3.  Coal,  upper  bench 1    ' 
4.  Shale \    4 
5.  Coal,  middle  bench 1 
6.  Shale ..  3 
7.  Basal  bench  of  massive  coal,  underlain  by  solid  white  sandstone ,r> 
The  second  exposure,  in  the  NW.  \,  sec.  9,  is  knows  as  the  Pratt  mine,  and  the  seam 
worked  at  this  place  probably  corresponds  to  the  upper  bench  of  the  bed  showing  in  the 
Rhodes  mine,  as  indicated  by  the  following  section: 
Section  at  Pratt  mim  . 
Ft.   in. 
1.  Sandstone,  partially  exposed. 
2.  Sbale 2    ff 
3.  Massive  coal 5 
4.  Slope,  talus  covered,  probably  shale  and  lower  coal  of  Rhodes  mine 9 
5.  Massive  white  sandstone 
Pleasant  Valley. — Several  coal  beds  have  been  prospected  in  T.  12  S.,  R.  7  E.,  and  some 
mining  is  being  done  for  local  consumption  in  sees.  30  and  31.  The  mine  in  the  NW.  \  SE.  \ 
sec.  30  shows  a  coal  bed  5  feet  10  inches  thick  that  is  clear  of  shaly  impurities  and  of  fair 
quality.  This  coal  is  believed  to  bo  the  same  as  the  coal  once  mined  in  the  NW.  \  sec. 
31,  where  a  tunnel  has  been  driven  through  the  hill  from  the  Winterquarters  mine.  On  the 
north  side  of  the  canyon,  in  sec.  31,  a  prospect  shows  4  feet  9  inches  of  clean  coal.  A  coal 
bed  lower  in  the  rocks  and  6  to  7  feet  thick  is  mined  near  the  bottom  of  the  canyon,  east  of 
the  center  of  sec.  31.  The  coal  from  this  mine  is  used  for  local  consumption  in  the  town  of 
Scofield.  A  coal  bed  has  been  prospected  very  near  the  west  side  of  the  SW.  \  sec.  11, 
and  both  prospected  and  mined  in  the  NW.  \  sec.  13,  T.  12  S.,  R.  7  E.  At  the  first  locality 
the  coal  is  3g  feet  thick,  while  at  the  second  3g  to  4  feet  of  coal  is  exposed,  the  base  being 
concealed.  In  each  instance  the  coal  rests  on  thick  white  sandstone.  This  coal  is  near  the 
top  of  the  coal-bearing  series.  A  coal  is  mined  for  local  use  near  the  center  of  sec.  2,  T.  12 
S.,  R.  6  E.  The  bed  is  4  feet  thick,  and  the  coal  seems  to  be  of  good  quality.  It  is  appar- 
ently stratigraphically  above  the  formation  recognized  as  coal  bearing  in  the  Book  Cliffs 
field.  Prospectors  who  have  worked  at  Winterquarters  and  Clear  Creek  are  of  the  opinion 
that  extensive  north-south  faults  occur  on  the  west  side  of  Pleasant  Valley,  and  that  these 
faults  explain  the  occurrence  of  coal  in  the  high  country  in  that  vicinity.  The  smooth  sur- 
face of  the  country  makes  it  exceedingly  difficult  to  demonstrate  the  existence  of  such 
faults,  and  without  the  evidence  of  definite  stratigraphic  correlation  it  can  not  be  asserted 
that  these  high  coals  are  to  be  classed  with  those  occurring  near  the  base  of  the  valley  at 
Scofield,  Winterquarters,  and  Clear  Creek. 
Scofield. — Mines  once  operated  by  the  Union  Pacific  Railroad  Company  are  located  one- 
half  mile  southeast  of  Scofield.  It  is  reported  on  reputable  authority  that  the  coal  is  25  to 
30  feet  thick.  Only  the  middle  portion  of  the  bed  was  worked,  it  is  explained,  because  the 
coal  formed  a  better  roof  than  the  overlying  shales.     A  cave-in  has  occurred  toward  the 
